Apparatus for producing fastener-element-free gaps in a continuous slider fastener chain

ABSTRACT

An apparatus is disclosed for producing fastener-element-free gaps in a continuous slide fastener chain. The apparatus comprises a punch block, a cutting punch reciprocally movable therein, and a die block positioned in oppositely spaced relation to said punch block and having a recess for receiving a group of fastener elements to be severed, said cutting punch having an upward stroke limited such that the distance between an extreme operating end of said punch and the bottom surface of said recess is smaller than the overall thickness of said fastener chain but larger than the thickness of said fastener elements. The arrangement of the apparatus ensures that adjacent longitudinal edges of the fastener stringer tapes are deflected upwardly progressively away from each other as the fastener chain is moved past the cutting punch so that a group of fastener elements severed off the deflected edges of said tapes along a length of the chain corresponding to a fastener-element-free gap to be produced.

United States atent n91 Kawakami 1 APPARATUS FOR PRODUCINGFASTENER-ELEMENT-FREE GAPS IN A CONTINUOUS SLIDER FASTENER CHAHN [75]Inventor: Koichi Kawakami, Toyama, Japan [73] Assignee: Yoshida KogyoKabushilki Kaisha,

Tokyo, Japan [22] Filed: June 7, 1973 [21] Appl. No.2 367,711

[30] Foreign Application Priority Data June 10, 1972 Japan 47-57938 I[56] References Cited UNITED STATES PATENTS 4/1964 Fasciano 83/921 X12/1965 Fasciano 83/921 X [451 May 28, 1974 Primary ExaminerFrank T.Yost [57] ABSTRACT An apparatus is disclosed for producingfastenerelement-free gaps in a continuous slide fastener chain. Theapparatus comprises a punch block, a cutting punch reciprocally movabletherein, and a die block positioned in oppositely spaced relation tosaid punch block and having a recess for receiving a group of fastenerelements to be severed, said cutting punch having an upward strokelimited such that the distance between an extreme operating end of saidpunch and the bottom surface of said recess is smaller than the overallthickness of said fastener chain but larger than the thickness of saidfastener elements.

The arrangement of the apparatus ensures that adjacent longitudinaledges of the fastener stringer tapes are deflected upwardlyprogressively away from each other as the fastener chain is moved pastthe cutting punch so that a group of fastener elements severed off thedeflected edges of said tapes along a length of the chain correspondingto a fastener-element-free gap to be produced.

2 Claims, 11 Drawing Figures i2 M m 9 PATENTEB NY 28 m4 SHEET 1 BF 3FIG.4

FI,G.5

BACKGROUND OF THE INVENTION This invention relates to apparatus forforming fastener-element-free gaps or spaces at predetermined intervalsin a continuous length slide fastener chain, more particularly a chainconsisting of a pair of oppositely disposed stringer tapes carryingalong their adjacent longitudinal edges two rows of interlockingfastener elements, the coupling parts of which elements on the onestringer tape extend into the longitudinal. edge region of the other ormating stringer tape when the fastener is closed.

There have been proposed many different apparatus for the production ofthe aforesaid fastener-elementfree gaps in a continuous fastener chainwhich are utilized for mounting sliders and end stop members onindividual lengths of slide fasteners made from the chain. Most of suchknown apparatus have involved means of spreading the two opposedstringer tapes apart by a distance large enough to permit of the entryof a cutting punch therebetween to sever a group of fastener elementsfrom the respective tapes. A typical example of such prior-art device isdesigned to pull the opposed stringer tapes transversely apart at thedesired location of a fastener-element-free gap to expose theinterengaged parts of the elements and thereafter cut the elementsbetween the pulled-apart adjacent edges of the tapes. However, thisdevice is liable to the drawback that the opposed tapes are not alwaysspread apart widely enough for the punch to move therebetween dependingupon the tension with which they are pulled apart, with the results thatthe adjacent tape edges are often marred or damaged by the punch whenoperated to remove the elements. Furthermore, the conventional apparatusis rather complicated with added means of pulling the tapes apart and istroublesome in the handling, adjustment and servicing of operating partsof the apparatus and hence it is not suitable for use for instance bytrouser manufacturers who would often prefer to buy a continuousfastener chain instead of measured individual fasteners and cut thechain to provide slide fasteners of desired product length at theirdiscretion.

SUMMARY OF THE INVENTION With the above noted difiiculties of theprior-art in view, the primary object of the present inveniton is toprovide an improved apparatus for the production offastener-element-free gaps in a continuous length fastener chain of thetype described, which apparatus is simple yet reliable in separating twoopposed stringer tapes apart and severing a group of fastener elementsalong a length corresponding to a desired element-free gap to be formed,without damaging the tape edges or the stitches holding the elementsthereto.

A more specific object of the invention resides in the provision of aninventive concept wherein there is provided a cutting punch having abifunctional performance firstly of spreading apart the stringer tapeswithout resort to any special added separating device and secondlycutting a length of fastener elements to produce a fastener-element-freegap as desired.

These and other objects and advantages of the invention will be betterunderstood from the following detailed description of some preferredembodiments taken in connection with the accompanying drawings whereinlike reference characters refer to like or corresponding partsthroughout the several views.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a plan view showing a segment of a continuous fastener chainhaving two interengaged stringer tapes and indicating a measured lengthof longitudinal space or gap to be produced therein;

FIG. 2 is a plan view similar to FIG. I but showing a cutting punchinterposed between and separating adjacent longitudinal edges of therespective stringer tapes at the said measured length of gap to beproduced;

FIG. 3 is a view similar to FIG. 2 but showing a group of fastenerelements just removed along the said measured length;

FIGS. 4 through 7 inclusive are diagrammatic views utilized to explainthe sequential steps of the process and the essential parts of theapparatus employed to carry the same into practice according to theinvention; FIG. 4 showing now the fastener chain is introduced into theapparatus; FIG. 5 showing how the fastener chain is deliveredprogressively toward and separated by the cutting punch; FIG. 6 showingthe adjacent longitudinal edges of two opposed stringer tapes spreadapart just prior to the severing of fastener elements; and'FIG. 7showing how the fastener elements are cut and removed from the stringertapes;

FIG. 8 is a diagrammatic front elevational view of the apparatus;

FIG. 9 is a cross-sectional view taken on the line AA of FIG. 8;

FIG. 10 is a plan view of a segment of continuous fastener chain havingproduced therein a modified form of a fastener-element-free gap; and

FIG. 11 is a diagrammatic view of the essential parts of apparatusdesigned to produce the said modified element-free gap.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawingsand FIGS. 1 to 3 in particular, there is shown a continuous slidefastener chain used in the practice of the invention, which chaingenerally designated at F comprises a pair of oppositely disposedstringer tapes T,T having mounted along their adjacent longitudinaledges Ta,Ta two rows of fastener elements E formed from a continuousplastic filament into a spiral or coil structure such that the couplingparts Ea in the row of elements on one stringer tape, when the fastenerchain is in closed disposition, extend into the longitudinal edge Ta ofthe other or mating stringer tape.

The rows of such fastener elements E are secured to the respectivestringer tapes T,T on one side thereof as by longitudinal lines ofstitches S,S (best shown in FIGS. 4, 6, 7 and 11).

The inventive concept of the present invention may be best understood byreference to FIGS. 4 to 7, which concept essentially comprisesdeflecting the adjacent longitudinal edges Ta,Ta of two stringer tapesT,T upwardly apart progressively by moving the fastener chain F inengagement with a cutting punch later described and cutting a group offastener elements E with said cutting punch along a length correspondingto a fastener-element-free gap to be formed in the chain F. Onepreferred form of apparatus employed according to the invention isillustrated in FIGS. 4 to 9, and referring to FIG. 9 in particular, thegap producing apparatus 10 comprises a support frame 1 1, a punch block12 and a die block 13, both blocks being housed in said frame 11. Thereis provided a cutting punch 14 mounted in the punch block 12 andvertically movable relative thereto by means of a suitable knownactuating mechanism not shown. The die block 13, which is disposed inopposite relationship to the punch block 12, is provided in its uppersurface with a recess 15 for receiving a group of fastener elements E.Centrally of the recess 15 is formed a punch receiving opening 16positioned in registry with the path of the cutting punch 14 anddimensioned to fit the width thereof. The punch receiving opening 16 isdefined by coacting cutting edges 17,17 which coact with the cuttingpunch 14, more specifically with bladed edges 14a thereof, in severin gthe elements E off the fastener chain F as best depicted in FIG. 7.

According to the principles of the invention, the fastener elementsreceiving recess 15 is dimensioned such that a distance H between thebottom surface 15a of the recess 15 on which the elements E are seatedand the operating end 14b of the cutting punch 14 in the limit of itsupward stroke is smaller than the overall thickness A of the fastenerchain F but larger than the thickness B of the fastener elements E perse, as best depicted in FIG. 4. This arrangement ensures that thecutting punch 14 can separate the adjacent longitudinal edges Ta,Ta ofthe opposed sctringer tapes T,T and cause the same to become deflectedupwardly apart as the fastener chain F is fed progressively through thepunch 14.

The position of the cutting punch 14 in which it func tions to separateor spread apart the adjacent edges Ta,Ta of the tape T,T; namely, therequisite distance H, can be secured by limiting or terminating theupward stroke of the punch 14 thereat for example with use of a suitablestopper means not shown in connection with the punch actuating mechanismas may readily occur to one skilled in the art.

The precise positioning of the cutting punch 14 as above describedfurther ensures that the tapes T,T are separated by a gap G formedtherein by the cutting punch 14 holding their respective adjacentlongitudinal edges Ta,Ta, plowed up away from each other, which gap G issustained exactly by the physical dimensions of the cutting punch 14particularly as regards the 'width thereof which defines a minimumrequired opening of the gap G, thereby eliminating the necessity of anyadded special separating device and assuring a fool-proof cutting of theelements E without the fear of damaging the tape fabric.

Designated at the reference numeral 18 is a cutter diagrammaticallyshown in FIGS. 8 and 9 for cutting the fastener chain F into individualfastener length after the chain F has been provided therein with anelement-free gap Ga. The construction and operation of the cutter 18 isconventional and hence will require no further explanation. The gapproducing apparatus 10 thus constructed operates in the followingmanner. The fastener chain F is first split at its leading end Fa alongthe opposed stringer edges Ta,Ta, without disengaging the interengagedrow of fastener elements E, by feeding the chain F horizontally throughthe apparatus in the direction of the arrow indicated in FIG. 8 and inthe manner depicted in FIG. 5. The chain F is thus moved, apredetermined distance until the desired location of an element-free gapto be produced arrives at the cutting punch 14, whereupon the punch 14is actuated to cut a group of elements E along a length of the chain Fcorresponding to the element-free gap Ga to be formed or the length L ofthe punch 14. This cutting operation is depicted in FIG. 7, wherein thecutting punch 14 moves vertically down into the opening 16 and in sodoing cuts the group of elements E centrally thereof and removes themfrom the chain F into the opening 16 which may be convenientlycommunicated to a collecting basket not shown.

The punch 14 is then retracted into a raised position as defined in FIG.4 is particular and the fastener chain F having thus formed therein theelement-free gap Ga is simply continued to move until the desiredlocation for the next gap Ga is registered with the cutting punch 14.

There is shown in FIG. 1 1 a modified form of apparatus according to theinvention which is characterized by the provision of an auxiliary cutter19 attached to the main cutting punch 14 for forming a side indent Gbadditionally in the region of the element-free gap Ga as shown in FIG.10, which is adaptable for attaching the fastener chain F to trouserflies or the like. The auxiliary cutter 19 has its tapered blade tip 19anormally positioned short of the operating end 14b of the punch 14 andabove the lower end 12a of the punch block 12, so that it does not comeinto contact with deflected edges Ta,Ta of the tapes T,T during theseparation thereof.

What is claimed is:

1. An apparatus for producing fastener-element-free gaps in a continuousslide fastener chain having a pair of oppositely disposed stringer tapescarrying along their adjacent longitudinal edges two rows ofinterlocking fastener elements, the coupling parts of which elements onthe one stringer tape extend into the longitudinal edge region of theother stringer tape when the fastener is closed, said apparatuscomprising a punch block, a cutting punch reciprocally movable therein,and a die block positioned in oppositely spaced relation to said punchblock and having a recess for receiving a group of fastener elements tobe severed and an opening formed centrally of said recess for receivingsaid cutting punch during the downward stroke thereof in which saidgroup of fastener elements is severed, said cutting punch having anupward stroke limited such that the distance between an extremeoperating end of said punch and the bottom surface of said recess issmaller than the overall thickness of said fastener chain but largerthan the thickness of said fastener elements.

2. The apparatus as defined in claim 1 which further includes anauxiliary cutter attached to said cutting punch, said cutter having abladed tip end situated up above the lower end of said punch block whensaid cutting punch is held in retracted position.

1. An apparatus for producing fastener-element-free gaps in a continuousslide fastener chain having a pair of oppositely disposed stringer tapescarrying along their adjacent longitudinal edges two rows ofinterlocking fastener elements, the coupling parts of which elements onthe one stringer tape extend into the longitudinal edge region of theother stringer tape when the fastener is closed, said apparatuscomprising a punch block, a cutting punch reciprocally movable therein,and a die block positioned in oppositely spaced relation to said punchblock and having a recess for receiving a group of fastener elements tobe severed and an opening formed centrally of said recess for receivingsaid cutting punch during the downward stroke thereof in which saidgroup of fastener elements is severed, said cutting punch having anupward stroke limited such that the distance between an extremeoperating end of said punch and the bottom surface of said recess issmaller than the overall thickness of said fastener chain but largerthan the thickness of said fastener elements.
 2. The apparatus asdefined in claim 1 which further includes an auxiliary cutter attachedto said cutting punch, said cutter having a bladed tip end situated upabove the lower end of said punch block when said cutting punch is heldin retracted position.